Alexion suffers defeat over Soliris patent at UK High Court

In the pan-European dispute over Soliris, Alexion has now suffered another defeat. The UK High Court found that an important patent relating to the active ingredient eculizumab would have to be revoked. The UPC had previously come to a similar conclusion.

Alexion has been defending several patents related to its biologic Soliris across courts in Europe. The orphan drug, based on the monoclonal antibody eculizumab, treats paroxysmal nocturnal haemoglobinuria (PNH).

PNH is a rare blood disorder that occurs when the immune system destroys red blood cells and platelets. Left untreated, it can cause haemolytic anaemia, chronic kidney disease or thrombosis. Soliris also treats other diseases such as atypical haemolytic uraemic syndrome, generalised myasthenia gravis and neuromyelitis optica.

Alexion’s latest dispute with Amgen and Samsung Bioepis concerns EP 3 167 888 B1, titled ‘Treatment of paroxysmal nocturnal hemoglobinuria patients by an inhibitor of complement’. Granted only last year, the patent is also subject to several oppositions. Amgen and Samsung Bioepis are among the opponents.

At the centre of the UK dispute was claim construction. According to the patent claim, the antibody is partly characterised by a light chain sequence with 22 extra amino acids. During prosecution, Alexion applied to amend the claims to define a light chain without the additional 22 amino acids. The EPO’s Technical Boards of Appeal rejected the application due to added matter objections (case ID: T1515/20). Thus, the EPO granted EP 888 on 1 May 2024 with claims defined in terms of the original application, having the 22 additional amino acids.

Samsung Bioepis and Amgen argue that their biosimilar products’ light chains will not have the additional 22 amino acids but rather the exact same sequence as eculizumab. Presiding judge Richard Meade found that, based on the claim construction, the patent would have to be revoked and was not infringed. Furthermore, he considered it unnecessary to decide on non-technical issues brought in the proceedings, such as abuse of process, judicial estoppel or approbation and reprobation, as this would not affect the overall result (case IDs: HP-2024-000020 and HP-2024-000021).

UPC rejects PI

Previously, the UPC had rejected a PI application filed by Alexion over the same patent. In a dispute involving the same parties, the court had expressed doubts that EP 888 would survive an opposition at the EPO. As a result, the local division Hamburg in July 2024 dismissed a PI application by Alexion against Samsung Bioepis and Amgen. An appeal by the patent holder was rejected by the Court of Appeal in Luxembourg later that same year (case IDs: UPC_CoA_402/2024 and UPC_CoA_405/2024).

The opponents are also fighting over different patents regarding eculizumab in Canada, as well as in revocation actions in the Netherlands and France. In Germany Alexion and Amgen were involved in a case concerning orphan drug exclusivity. In the dispute, the Munich Regional Court has referred a request for a preliminary ruling to the CJEU (case ID: C-814/24).